EMD-31322

Single-particle
10.2 Å
EMD-31322 Deposition: 17/05/2021
Map released: 22/09/2021
Last modified: 22/09/2021
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-31322

portal-tail complex of LPS-treated full bacteriophage T7

EMD-31322

Single-particle
10.2 Å
EMD-31322 Deposition: 17/05/2021
Map released: 22/09/2021
Last modified: 22/09/2021
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Escherichia phage T7
Sample: Escherichia phage T7

Deposition Authors: Liu HR, Chen WY
Structural changes in bacteriophage T7 upon receptor-induced genome ejection.
Chen W , Xiao H , Wang L, Wang X, Tan Z , Han Z , Li X, Yang F, Liu Z , Song J , Liu H , Cheng L
(2021) PNAS , 118
PUBMED: 34504014
DOI: doi:10.1073/pnas.2102003118
ISSN: 1091-6490
ASTM: PNASA6
Abstract:
Many tailed bacteriophages assemble ejection proteins and a portal-tail complex at a unique vertex of the capsid. The ejection proteins form a transenvelope channel extending the portal-tail channel for the delivery of genomic DNA in cell infection. Here, we report the structure of the mature bacteriophage T7, including the ejection proteins, as well as the structures of the full and empty T7 particles in complex with their cell receptor lipopolysaccharide. Our near-atomic-resolution reconstruction shows that the ejection proteins in the mature T7 assemble into a core, which comprises a fourfold gene product 16 (gp16) ring, an eightfold gp15 ring, and a putative eightfold gp14 ring. The gp15 and gp16 are mainly composed of helix bundles, and gp16 harbors a lytic transglycosylase domain for degrading the bacterial peptidoglycan layer. When interacting with the lipopolysaccharide, the T7 tail nozzle opens. Six copies of gp14 anchor to the tail nozzle, extending the nozzle across the lipopolysaccharide lipid bilayer. The structures of gp15 and gp16 in the mature T7 suggest that they should undergo remarkable conformational changes to form the transenvelope channel. Hydrophobic α-helices were observed in gp16 but not in gp15, suggesting that gp15 forms the channel in the hydrophilic periplasm and gp16 forms the channel in the cytoplasmic membrane.